The present invention relates to a solid electrolyte fuel cell and a process for the production thereof and more particularly to a solid electrolyte fuel cell comprising a cathode layer formed on one side of a solid electrolyte layer and an anode layer formed on the other side of the solid electrolyte layer and a process for the production thereof.
Patent Reference 1 cited below proposes a simple fuel cell which can be disposed in a burning flame or in the vicinity thereof to generate electricity. This fuel cell is shown in FIG. 13. A fuel cell 100 shown in FIG. 13 comprises a cathode layer 104 formed on one side of a solid electrolyte layer 102 having a dense structure and an anode layer 110 formed on the other side of the solid electrolyte layer 102 (hereinafter referred to as “solid electrolyte fuel cell 100”). The cathode layer 104 and the anode layer 110 each are in the form of porous layer and have mesh metals 106, 112 embedded therein or fixed thereto. From these mesh metals 106, 112 extend lead wires 103, 114.    [Patent Reference 1] JP-A-2005-63686
When the solid electrolyte fuel cell 100 shown in FIG. 13 is disposed in or in the vicinity of burning flame on the anode layer 110 side thereof, electricity can be generated and outputted at the lead wires 108, 114.
However, when the solid electrolyte fuel cell 100 shown in FIG. 13 is repeatedly exposed to flame (thermal shock) on the anode layer side 110 thereof, there occurs a phenomenon that the electric power (shown by the solid circle in FIG. 14) outputted at the lead wires 108, 114 shows a gradual drop as shown by the arrow A in FIG. 14 illustrating the electricity-generating properties of the solid electrolyte fuel cell 100, demonstrating that the solid electrolyte fuel cell 100 is poor in durability. Further, the electric power outputted at the lead wires 108, 114 is insufficient. Therefore, the solid electrolyte fuel cell 100 shown in FIG. 13 leaves something to be desired in durability and electric power outputted.
In FIG. 14, the blank circle indicates voltage outputted at the lead wires 108, 114.
In order to study the reason why the solid electrolyte fuel cell 100 shown in FIG. 13 is poor in durability, the inventors observes electron-microphotographically a section of the solid electrolyte fuel cell 100 which is repeatedly exposed to flame on the anode layer 110 side thereof. As a result, it is found as shown in FIG. 15 that the interface of the porous cathode layer 104 with the solid electrolyte layer 102 having a dense structure undergoes exfoliation and the solid electrolyte layer 102 undergoes cracking.
It is further observed that the adhesion between the metal wire constituting the mesh metal embedded in the cathode layer 104 and the cathode layer 104 is deteriorated.